Rear End Shake

[Embraer]

So I'm driving along, and sometimes the problem happens; sometimes it doesn't.

Here are the symptoms:

When I accelerate from 0-65, when I reach 65, the right rear end shakes like one of the tires is oblong. I have brand new tires, that ARE balanced correctly.

If I accelerate very leisurely up to 65, it usually doesn't happen.

I talked with a Porsche shop here over the phone, and he said the rear shocks are probably shot. I just wanted some other opinions here. I'm going to tear into this weekend to see if I can see anything.

Maybe a warped rotor? Bad shock?

The car is a turbo-look with 2" spacers in the rear. When I jack the car up and spin the wheels, it doesn't seem out of round or shimmy back and forth.

Thanks!!

Mike

[Paulporsche]

Could be any of those things mentioned.

Were the wheels balanced on the car w/ the spacers? If not, try removing and/or swapping them and see what happens.

It's also possible the tire is defective internally, say bad belts.

[porsche930dude]

I would pull the shocks and test them by hand and swap them if they seem good that will tell you if there bad. The only other thing that comes to mind that hasnt been mentioned is the cv joints maby the bolts are loose

[Embraer]

Thank you guys......Paul, I had them high speed balance them off of the car. I did some straight edge/leveling measurements and the spacers are sitting flush, with no wobble.

I'll check the CV joint bolts....I kind of have a suspicion that those might be the culprit. It's a pretty violent shake when it happens...not subtle at all. In fact, I'm kind of worried, because that shaking has to be stressing other components back there (ie bearings)....

we'll see tomorrow...

[Embraer]

Great signature quote, Porsche930dude....one of my favorite movies

[Embraer]

Took the shocks off...they were fine (hard to compress by hand, but do-able). I checked the bolts on the CV joints....they were all nice and tight. The bushings all below look fine, as well.

Argh....

[mossguy]

Any chance this could be a rear wheel bearing problem?

Tom

[crashmy911]

check your bushings also. I would think wheel bearings or cv joints.

[Charlie V]

I would also suggest checking the rear axle nuts too.

I used smaller sized cotter pins - what I had in the shop at the time - and the nuts backed off and sheared the cotter pins.

Good luck.

[BlueSideUp]

How long has it been since your CV joints were repacked with new grease? When you are accelerating hard the angle of the axles changes as weight is quickly shifted to the rear. If the joints aren't greased well they will jam up and cause a bad vibration as you describe.

Try some of the easier things before pulling the axles.

[Embraer]

Rear axle nuts are tight....

BlueSideUp, I'll have to check the CV joint grease. This is a new SC for me, so Im unsure of that status. When I logically think about it...given the way it feels, I think it's something that has to do with the CV joint.

Thanks for the input!!!

[porsche930dude]

Maby try jacking the rear end up and let the wheels sag at full droop and run it slow with the parking brake on a little bit. If it makes weird noises their bad

[mossguy]

Porsche930 dude; I assume you are referring to noise in the CV joint(s) and not the the parking brake. Is that correct?

Thanks,

Tom

[Embraer]

curious, as well.

thanks!